Loom dobbies



Aug. 12, 1969 T. HINDLE 3,460,58 LOOM DOBBIES Fi led Aug. 31, 1967 INVENTOR:

United States Patent US. Cl. 139-68 6 Claims ABSTRACT OF THE DISCLOSURE A jack lever device for a loom dobby wherein a primary lever has a secondary lever pivotally mounted thereon which is coupled to a heald frame, the secondary lever being angularly adjustable relative to the primary lever to provide a ready means of adjusting the heald frame when in position in a loom.

The invention concerns loom dobbies and has particular reference to jack levers, especially but not exclusively horizontally disposed jack levers.

Conventional horizontal jack levers as used in weaving looms for the positional control of heald frames esspecially those looms used for the weaving of wide felts of the kind used in the papermaking industry, do not readily lend themselves to adjustment and, when it is required to raise or lower a given heald frame relative to an adjacent frame or frames as distinct from levelling a frame, adjustment of the frame or frames is usually effected by means of turnbuckles disposed above and below the frame in the tie-ups therefor. Whilst such an adjustment does achieve the desired result, it does present the disadvantage that the adjustment is effected within the loom and furthermore necessitates the manual adjustment of four or more turnbuckles.

The primary object of the present invention is to provide a jack lever device whereby the adjustment can be effected in a simple and accurate manner so as to avoid the need manually to adjust the turnbuckles or other like heald frame support elements.

According to the present invention a jack lever device comprises a primary lever (which is a lever of the third order) supported in a bearing means for pivotal motion relative thereto, a secondary lever pivotally connected to the said primary lever and adapted to be coupled to the heald frame, and an adjustment means whereby the relative angular positions of the primary and secondary levers is adjustable.

Preferably the second part will extend beyond the first part longitudinally thereof.

The invention will now be described further, by way of example only with reference to the accompanying diagrammatic drawings in which:

FIG. 1 is a front elevation, partly broken away of a horizontal jack lever;

FIG. 2 is a plan view of the embodiment shown in FIG. 1; and

FIG. 3 is a view corresponding to a part of FIG. 1 and shows an alternative embodiment.

Referring now to FIG. 1 of the drawings, a jack lever comprises a primary lever 11 mounted for pivotal movement relative to an axle 12, a secondary lever 13 pivotally supported on the said primary lever 11 at the forward end of the latter, and an adjustment means 14 arranged to locate and to maintain the first and second levers in a requisite relative angular position one to the other. It will be noted that the primary lever 11 is a lever of the third order, that is to say, the actuating force is applied to its midportion, the fulcrum being at one end and the load being at the opposite end. On the other hand, the secondary lever 13 is a lever of the first order, the load being at one end, the fulcrum between the ends and the actuating force at the opposite end.

The primary lever 11 is constituted by two spaced parallel elements (see particularly FIG. 2), arranged in face-to-face disposition and pivotally connected, at a point intermediate their length, to a power-driven actuating element 15 whereby the said primary lever, is caused to execute an oscillatory motion about axle 12. The elements 11a are joined together at the upper and lower edges thereof by plates 11b, the upper and lower plates being aligned one with the other and each of the said. plates having a screw-threaded hole therein.

The secondary lever 13 has a downwardly directed offset or clearance portion which is of truncated V- shape, the distal end of this secondary lever being interposed between adjusting screws 11b having screw-threaded engagement with openings in lugs lle projecting from that portion of the primary lever which is adjacent to its fulcrumed end.

The primary and secondary levers 11 and 13 are pivotally connected together, with the secondary lever 12 positioned between the spaced elements 11a of the primary lever, by a pin 16 passing between the opposed elements 11a and upon which the secondary lever is mounted, such pin 16 being located adjacent the distal end of the primary lever and passing through the secondary lever in spaced disposition relative to the outer end thereof, the other end of the secondary lever extending to a position in which it lies between the lugs 11b.

A lock bolt 17 is in screw-threaded engagement with holes in each of the plates 11b and respectively the two bolts bear on the opposite sides of the inner end of the secondary lever. The plates 11a, the bolts 17 and the inner end 13a of the secondary lever collectively define the adjustment means 14 aforesaid.

The distal end of the secondary lever 13 is firmly attached to the heald harness 18 such that vertical movements of the said end consequent upon pivotal motion of the primary lever 11 due to the activating element 15 effect longitudinal displacements of the harness in an appropriate sense.

During normal usage the device illustrated in the drawings will periodically rise and fall under the control of the actuating element 15 and thus the harness 18 will be moved in step therewith, raising or lowering the related heald frame.

If it is desired to adjust the position of any given frame or frames relative to the adjacent frame or frames, for example, an adjustment such as might be required to achieve a particular characteristic in the cloth being woven, then the relative angular position of the two parts 11, 13 of the lever device of the heald frame to be adjusted is adjusted by loosening the lock bolts 17, moving the two levers 11, 13 to the required relative disposition and retightening such bolts, such an operation causing the harness 18 to move longitudinally and thus the heald frame to move up or down as appropriate.

The invention is not restricted to the exact features of the embodiment hereinbefore described since alternatives will readily present themselves to one skilled in the art.

Thus, for example, Whilst it is desirable from strength considerations, particularly when wide looms are involved and thus the heald frame weight is considerable, to locate the secondary lever between spaced elements which collectively define the primary lever, in some circumstances an adequate strength is attainable with other constructions. In an alternative arrangement see now FIG. 3, the adjustment means is constituted by a plate 21a rigidly secured to the primary lever 21 and located between parts 21a and 22a of the bifurcated end of the secondary lever 22, appropriate screw bolt means 23 being provided to eflect the adjustment.

It may 'be noted by inspection of FIG. 1 of the drawings that the arm 13b of the secondary lever is much shorter than the other arm with whose free end the adjusting devices are associated. By such an arrangement a very accurate adjustment of the heald frame may be made.

Various other arrangements for eifecting adjustment will, of course readily present themselves to one skilled in the art and it is not intended that the examples illustrated be considered exhaustive of the possibilities. Furthermore, whilst the invention is principally concerned with horizontal jack levers, the invention is equally applicable to levers arranged in some other disposition.

I claim:

1. In a loom having a heald frame, a jack lever device comprising a primary lever and a secondary lever, the secondary lever being pivotally secured to the primary lever intermediate its ends thus providing two arms, the pivotal point being such that one of the arms is substantially longer than the other, and means whereby the shorter arm may be connected with the heald frame, and means for adjusting the end of the longer arm relatively to the primary lever.

2. A jack lever device according to claim 1, further characterized in that the adjusting means comprises a screw-threaded part having threaded engagement with one of said levers and whose end engages a part of the other lever.

3. A jack lever device according to claim 1, further characterized in that the primary lever comprises two spaced, parallel members rigidly united by bridging plates, each of said plates having a screw-threaded hole, and adjusting screws engaging the holes in the respective plates and whose opposite ends engage a part of the secondary lever.

4. A jack lever device as claimed in claim 1, wherein the secondary lever has a downwardly directed offset intermediate its point of attachment to the primary lever and that region thereof which receives the adjustment means, and an actuating element connected to the primary lever in a region thereof corresponding to the ofiset portion of the second lever.

5. A jack lever device for actuating a heald frame of a loom, said device comprising a lever of the third order fulcrumed at one end to a fixed support and connected at its midportion to a power-driven actuating device, and a secondary lever, which is of the first order and Whose midportion is fulcrumed to the distal end of the primary lever, one arm of said secondary lever projecting outwardly beyond the distal end of the primary lever and having means for connecting its outer end to a heald frame, the other arm of the secondary lever extending lengthwise of the primary lever and having its opposite end adjacent to the fulcrum of the primary lever, and means for adjusting the last-named end of the secondary lever relatively to the primary lever, thereby to change the angularity of the primary and secondary levers and so to adjust the limits of displacement of the heald frame.

6. A jack lever device operative to actuate a heald frame of a loom, said device comprising a primary lever fulcrumed at one end to a fixed support and a secondary lever fulcrumed at a point between its ends to the free end portion of the primary lever, one arm of the secondary lever extending beyond the free end of the primary lever and being connected to a. heald frame, and the other arm of the secondary lever extending toward the fulcrum of the primary lever and terminating adjacent to said fulcrum, means for adjusting the last-named end of the secondary lever relatively to the primary lever, the last-named arm of the secondary lever 'being substantially longer than the other arm, and means for connecting the last-named arm to a heald frame.

References Cited UNITED STATES PATENTS 971,764 10/1910 Lutz 74-522 2,681,078 6/1952 Picanol 139-79 3,041,888 7/1962 Dehn 74522 HENRY S. JAUDON, Primary Examiner U.S. c1. X.R. 74-519; 139 79 

